As a conventional storage system, an automatic warehouse is known which is provided with a storage area constituted by an indoor floor face (concrete face) or the like formed so as to stack and store products in plural stages according to type, a warehousing area provided adjacently to the storage area and for carrying in products stacked on a pallet from outside, a delivery area provided adjacently to the storage area and for carrying out the stored products by stacking them on an empty pallet according to a request, a transfer apparatus for warehousing that is arranged on a ceiling region and capable of three-dimensional movement so as to transfer products from the warehousing area to the storage area, a transfer apparatus for delivery that is arranged on the ceiling region and capable of three-dimensional movement so as to transfer products from the storage area to the delivery area and the like (See Patent Document 1, for example).
However, in this storage system, the products carried into the warehousing area and in a standby state are sorted according to types thereof and stored in the storage area and then, the same type of products are transferred onto a pallet standing by in the delivery area according to a delivery instruction and carried out to a required outside area (subsequent process where the products are required, for example) from the storage area. That is, since a transfer operation of the products is processed in two stages, namely, a warehousing and transfer operation from the warehousing area to the storage area and a delivery and transfer operation from the storage area to the delivery area, time required for storage processing gets long, and efficiency of the storage processing is drastically lowered.
Also, since the transfer apparatuses for performing the storage processing are separate, which are the transfer apparatus for carrying-in (warehousing) for transferring the products from the warehousing area to the storage area and the transfer apparatus for carry-out (delivery) for transferring the products from the storage area to the delivery area, if the balance between warehousing and delivery of the products becomes wrong, an operation efficiency of the storage processing is lowered, in a manufacturing process or the like using the product, an influence given on a prior process or subsequent process becomes significant.
Also, since the storage area is constituted by an indoor floor face (concrete face) or the like, the products are directly stacked on the floor face according to type and masses of the stacked products are stored in a planarly arranged state and in close contact (adjacently) with each other, once they are stacked and arranged, it is difficult to move the stacked products to another region within the storage area, and an allocated region for stacking the products within the storage area cannot be changed easily.
Moreover, since the warehousing area and the delivery area are planarly arranged as separate areas adjacent to an outer periphery of the storage area, if a product is to be transferred from the warehousing area to the farthest allocated region (stacking region) of the storage area or if the product is to be transferred from the farthest allocated region (stacking region) of the storage area to the delivery area, a moving distance of the transfer apparatus becomes long, which incurs deterioration of the transfer efficiency (storage processing).    Patent Document 1: Japanese Unexamined Patent Publication No. 2000-238906